D.D. Carmony

The role of double parton collisions in soft hadron interactions

Abstract We have examined charged multiplicities arising from p−p and p− p collisions over the range of center of mass energies, s , from 30 GeV to 1800 GeV. Results from Tevatron experiment E735 support the presence of double parton interactions. These processes can be seen to account for a large fraction of the increase in the non single diffraction inelastic cross section from energies of about 200 GeV to 1800 GeV.

Charged particle multiplicity correlations in pp̄ collisions at s=0.3−1.8 TeV

Abstract The correlations between charged particle multiplicitie produced in forward and backward pseudorapidity regions in pp interactions have been measured with a 240 element scintillator hodoscope. The correlation coefficient and the variance of the difference of multiplicities in the two pseudorapidity regions were deterermined for s =0.3−1.8 TeV . These results have been interpreted in terms of a cluster model of particle production.

Inclusive ηp and ηn charged-current neutrino reactions below 6 GeV☆

Abstract Results are presented of a study of inclusive ηp and ηn interactions from threshold to 6 GeV. The data show a rapid approach to the distributions expected in the naive quark-parton model. The charged-current η deuteron total cross section is fit by the expression σ T ( η d) = (0.76 ± 0.03) × 10 −38 E η cm 2 per GeV per nucleon. For E η > 1.5 GeV, we measure σ T ( η n)/ σ T ( η p) = (2.02 ± 0.23). The distributions in the scaling variables x and y are given and discussed.

Evidence for hadronic deconfinement in p̄–p collisions at 1.8 TeV

Abstract We have measured deconfined hadronic volumes, 4.4 V 3 , produced by a one-dimensional (1D) expansion. These volumes are directly proportional to the charged particle pseudorapidity densities 6.75 dN c / dη T =179.5±5(syst) MeV. Using Bjorkens 1D model, the hadronization energy density is ϵ F =1.10±0.26(stat) GeV/fm 3 corresponding to an excitation of 24.8±6.2(stat) quark–gluon degrees of freedom.

Charged particle multiplicity correlations in

Abstract The correlations between charged particle multiplicitie produced in forward and backward pseudorapidity regions in pp interactions have been measured with a 240 element scintillator hodoscope. The correlation coefficient and the variance of the difference of multiplicities in the two pseudorapidity regions were deterermined for s =0.3−1.8 TeV . These results have been interpreted in terms of a cluster model of particle production.

p\bar{p}

Transverse momentum spectra of charged particles produced within the pseudo-rapidity range of η= − 0.36 to + 1.0 have been measured in pp collisions at √s=0.3, 0.54, 1.0, and 1.8 TeV. The spectra are presented as a function of event charged multiplicity within the range −3.25<η<3.25. We found that the slope in the low pt region is independent of center-of-mass energy and multiplicity while the slope at the high pt region shows a strong energy and multiplicity dependence.

collisions at

Abstract Using new ν p charged-current data from the Fermilab 15 foot hydrogen bubble chamber, some properties of the ν -induced hadronic jets are studied. The angular size of the jets is measured and compared with results from e + e − annihilation. The jets in the two processes are found to be quite similar in terms of the variables sphericity, thrust, and energy flow.

\sqrt{s}

Abstract We have measured the excitation function for the neutral current process νn→νpπ− as a function of neutrino energy. Our data give a cross section ratio R=σ(νpπ−)/σ(μ−pπ+)=0.11±0.022 over the energy interval (0.3⩽E ν⩽1.5)GeV. This measurement of single-pion production in a kinematically defined reaction is the first to use a deuterium target. The R value, as well as other characteristics of the data, agrees with the Adler model for single-pion production via the neutral current and gives a value of sin2θw=0.26±0.09.

= 0.3-TeV to 1.8-TeV

Abstract Using data from the Fermilab 15 ft hydrogen bubble chamber, we have studied inclusive ϱ0 production in antineutrino-proton charged-current interactions. We measure (0.21 ± 0.03) ϱ0/event, corresponding to ϱ0/π−=0.12 ± 0.02. As a function of Q2 and for hadronic masses above a threshold region, the ϱ0/π− ratio shows little variation. At least 50% of the ϱ0s are consistent with coming from the current fragmentation region. The results agree reasonably well with the predictions of the quark fragmentation model of Feynman and field.

Multiplicity dependence of transverse momentum spectra of centrally produced hadrons in pp collisions at 0.3, 0.54, 0.9, and 1.8 TeV center of mass energy

Abstract The hadronic system produced in charged-current antineutrino interactions is used to study fragmentation of the d-quark. Some problems encountered in defining the current quark fragments are discussed. The properties of the fragmentation function are in good agreement with the expectations of the naive quark-parton model and, in particular, at the present level of statistics we find no need for either a Q 2 -or an x BJ -dependence.